The present invention relates to a split-flange connector. More particularly this invention concerns a method of making such a connector.
These are loose flange connections for pipe or hose connections on hydraulic parts, for example, mobile devices, like dredgers, cranes etc., as well as rolling mills and other known devices. Such a flange consists of forged material or malleable cast iron. The mold corresponds to the illustration in accordance with FIGS. 1 and 2, however in view of the required hardness, caused by the manufacturing process between the two screw bores of half a flange (flange half shell), a curved shaped rib is provided which extends to the proximity of the screw threads. Therefore, not sufficient space is left for applying a fixed wrench, so that a tightening can be performed only at small angles, i.e., one has to apply the fixed wrench again and again. Socket wrenches do not find space because the dimension of the screw does not leave any space for the center bore. Furthermore, the rib constitutes the additional waste of material because it corresponds at its highest point to the flange thickness in the screw bore area. Furthermore, it is disadvantageous in the known embodiments that the flange half shells cannot be made in any desired hardness; this is particularly true for the flange half shells made of malleable cast iron. Finally, too much waste is generated and one must operate with a high energy consumption because of the high temperatures and the many aftertreatment steps, respectively. Furthermore, the engagement faces facing each other must be subsequently treated because the cutting thickness of the saw blade is lost at this location if the half shell is made by cutting open a flange which had been extruded as a total unit. As is known, half shells are required because one cannot mount a flange as a total unit onto the bore end or the coupling piece. Finally, a precise positioning with respect to the pinhole image of a pump or hydraulic, for example, is not possible. Therefore, at first, the one half flange must be mounted during assembly and then the second one must be subsequently attached. Thereby, difficulties are already generated, in particular because a precise centering is not possible, since each screw bore will be larger than the screw to be introduced. In other words, the mounted flange is displaced and the supporting faces of the screws with respect to the screw bores are not centrically disposed. When tightening the screws one does not have a uniform force pressure. Since, in addition, the screw material is harder, for example, than the malleable cast iron material or the forged half shells, the screws will loosen because the material of the flange half shells flows due to the high tightening pressure; a continuous subsequent tightening is required.